The present invention relates to devices for securing bathtubs to walls, and to devices for preventing moisture from the tub or shower from entering the surrounding walls. More particularly, the present invention relates to a flexible, extrusion molded flange, which snaps onto the edge of a tub and provides a means for securing the tub against the wall while simultaneously forming a moisture barrier between the tub deck, the finish wall, and the underlying drywall.
Moisture penetration of the crack between a bathtub deck and the surrounding walls can damage the walls and flooring beneath the tub. Because of the tub's weight, especially when filled water and a person using the tub, tub installations present the additional problem of the tub tending to pull away from the surrounding wall. Several methods have been invented to secure the tub against the surrounding walls and to create a moisture barrier between the tub deck and the walls.
U.S. Pat. No. 4,204,376 to Calvert (1980) teaches a molding which engages the edge of the bathtub and through which the tub is secured to the wall by nails being driven through the molding and the bathtub flange into the wall. Such a system secures the tub to the wall, but does not provide a moisture barrier.
U.S. Pat. No. 4,290,154 to Benjamin (1981) also teaches a wall-mounted bracket attached to the edge of a bathtub, the bracket being anchored to the wall with nails or screws. The tub deck is provided with a rib upon which the drywall or finish wall can be rested, but a moisture barrier is absent and caulking or grouting is essential.
U.S. Pat. No. 4,837,997 to Zeilinger (1989) addresses the problem of sealing the crack between the tub deck and the wall. Zeilinger teaches a sealing system including three generally L-shaped sealing strips and a corner piece for covering the corner where the joints meet. The sealing strips and corner pieces are held in place against the wall and tub deck with a suitable adhesive. While such sealing systems may provide an effective barrier to moisture entry between the tub deck and the wall, they do not simultaneously solve the problem of supporting the weight of the bathtub against the wall.
Modern building codes are increasingly requiring that bathtubs intended for installation against a wall incorporate a raised flange which extends at least 7.9 mm (5/16 inch) above the tub deck, which should form an effective moisture barrier between the tub and flange. See American National Standards, ANSI 7-124.1-1995.
While prior art tub support flanges, such as the Crane Snap-on Flange, provide tub support and some moisture barrier properties, it provides no specific moisture barrier between the finish wall and drywall, nor any edge upon which to align and seal the finish wall (typically ceramic tiles).